Albert Barnes Commentary Psalms 115:15

"Blessed are ye of Jehovah, Who made heaven and earth." — Psalms 115:15 (ASV)

You are blessed of the Lord – Blessed in your present comforts and mercies; blessed in his promises regarding the time to come; blessed in the prospects which are before you.

which made heaven and earth – The true God; the great Creator of all things. It was not the blessing of a creature – man or angel – it was the blessing of the living God.